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Most of the sub-folders under Inbox or Archives are suddenly no longer there. These are still accessible through the web or on my phone. Any suggestions?

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Yesterday I had 5 sub-folders under Inbox and about 10 in Archives (in my main email account). Now none of those exist in Thunderbird except for 2 random ones in Archives. Mild panic until I saw all the folders and emails within them exist on my phone or when accessed through web mail. I usually live in Thunderbird all day so naturally this issue messes with that. I'd appreciate any insight to resolving this. Thank you.

Yesterday I had 5 sub-folders under Inbox and about 10 in Archives (in my main email account). Now none of those exist in Thunderbird except for 2 random ones in Archives. Mild panic until I saw all the folders and emails within them exist on my phone or when accessed through web mail. I usually live in Thunderbird all day so naturally this issue messes with that. I'd appreciate any insight to resolving this. Thank you.

Chosen solution

I started to answer for fixing these corrupt folders in Thunderbird, then figured it would be easier and safer if you just re-create the e-mail account in Thunderbird instead. All you would lose are your message filters (if you have any), but you can get the file holding the messages filters for your account, and add it to the files for the new account.

When you remove an account from Thunderbird, it does not delete the files for that account from the hard drive, thus those files are still accessible later.

1. First, just to be safe and keep some piece of mind, Backup the Thunderbird Profile folder. It holds all your personal data such as messages, address books, calendars and configuration settings in a hard drive folder called the Profile. This folder is separate from the installation of Thunderbird.

2. Right-click your account in the normal folder view of Thunderbird and choose Settings.

3. Click the Account Actions button on the bottom left side and choose Remove Account.

4. Click the Account Actions button again, this time choosing Add Mail Account.

5. Set up your e-mail account again.

6. When finished setting up your e-mail account, click OK on the Account Settings window.

7. Quit Thunderbird, wait a few seconds, then start Thunderbird again.

The new account will be working.

If you had message filters in the account before: We need to copy the file msgFilterRules.dat from the old account files to the new account files on the hard drive.

8. Find & open your Thunderbird Profile folder:

Select Help: Troubleshooting Information from the Thunderbird menu (either from the menu button , on the top right, or the normal menu at the top of the window.)

Under "Application Basics", beside "Profile Folder", click the "Show Profile" button.  This will open a window showing the contents of your Thunderbird Profile folder.

9. Quit Thunderbird, but keep that window open showing your Thunderbird Profile folder.

10. In the Profile folder, find and open the folder called ImapMail.

11. In this folder will be folders for every IMAP account you ever had in Thunderbird. Each will have the name of the incoming mail server for each account. If you are lucky, you only have two with the name of your incoming mail server, one with "-1" inserted into the name to show that it is another for the same server. It will be the new one. The folder name without that number will be the original one. In the folder for the original one, find and copy the file msgFilterRules.dat. Then go into the folder for the new account, and paste this file there, replacing the one that was created automatically when you created the account.

12. Start Thunderbird. You should have your message filters back for that account.

If somewhere along the line something goes wrong, you have the backup of your original Profile folder (Step #1), to use to fix things.

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Chosen Solution

I started to answer for fixing these corrupt folders in Thunderbird, then figured it would be easier and safer if you just re-create the e-mail account in Thunderbird instead. All you would lose are your message filters (if you have any), but you can get the file holding the messages filters for your account, and add it to the files for the new account.

When you remove an account from Thunderbird, it does not delete the files for that account from the hard drive, thus those files are still accessible later.

1. First, just to be safe and keep some piece of mind, Backup the Thunderbird Profile folder. It holds all your personal data such as messages, address books, calendars and configuration settings in a hard drive folder called the Profile. This folder is separate from the installation of Thunderbird.

2. Right-click your account in the normal folder view of Thunderbird and choose Settings.

3. Click the Account Actions button on the bottom left side and choose Remove Account.

4. Click the Account Actions button again, this time choosing Add Mail Account.

5. Set up your e-mail account again.

6. When finished setting up your e-mail account, click OK on the Account Settings window.

7. Quit Thunderbird, wait a few seconds, then start Thunderbird again.

The new account will be working.

If you had message filters in the account before: We need to copy the file msgFilterRules.dat from the old account files to the new account files on the hard drive.

8. Find & open your Thunderbird Profile folder:

Select Help: Troubleshooting Information from the Thunderbird menu (either from the menu button , on the top right, or the normal menu at the top of the window.)

Under "Application Basics", beside "Profile Folder", click the "Show Profile" button.  This will open a window showing the contents of your Thunderbird Profile folder.

9. Quit Thunderbird, but keep that window open showing your Thunderbird Profile folder.

10. In the Profile folder, find and open the folder called ImapMail.

11. In this folder will be folders for every IMAP account you ever had in Thunderbird. Each will have the name of the incoming mail server for each account. If you are lucky, you only have two with the name of your incoming mail server, one with "-1" inserted into the name to show that it is another for the same server. It will be the new one. The folder name without that number will be the original one. In the folder for the original one, find and copy the file msgFilterRules.dat. Then go into the folder for the new account, and paste this file there, replacing the one that was created automatically when you created the account.

12. Start Thunderbird. You should have your message filters back for that account.

If somewhere along the line something goes wrong, you have the backup of your original Profile folder (Step #1), to use to fix things.